1. Field of the invention.
The present invention relates to systems for the treatment of water or liquid within cooling towers, and more particularly, to such systems wherein bleed-off water is ejected from the system.
2. Description of the related art.
A problem which is quite prevalent in heating or cooling systems and apparatus which use large amounts of water, such as boilers, cooling towers and the like, is that of scale buildup on the surfaces which come into contact with the water. This is especially troublesome in areas where the water has a high mineral content so that it is necessary for the water to be "conditioned" either by chemical action or by magnetic water treatment devices.
One such magnetic treatment device for use in a cooling tower is disclosed in U.S. Pat. No. 3,951,807 to Charles H. Sanderson and comprises an elongated magnet having a multiplicity of longitudinally spaced poles encased in a non-magnetic jacket and concentrically positioned within an outer casing made of a magnetic material. The jacketed magnet is centered by means of a pair of stepped collars secured thereto which in turn are centered by means of a pair of flared inserts.
Magnetic treatment devices generally of this type are well known and prevent the buildup of scale by causing the calcium and other minerals present in hard water to form, instead, a loose slurry which can be easily removed from the system by blow-down or flushing. The effectiveness with which the water is treated depends on the intensity of the magnetic field within the treating chamber and the effective length of the chamber itself. Accordingly, it is desirable that the chamber be free of any obstructions which may occupy otherwise available treatment space, and for the water to be directed as many times as possible through the treatment chamber.
Boilers and cooling tower systems conventionally are treated with chemicals for the control of scale buildup. These systems require that portions of the heat conducting liquid containing the accumulated dissolved solids be bled off, i.e. removed, from the system. This bleed-off or blow-down water has in the past been simply flushed down the sewer, thereby increasing the sewer bills for the particular installation while at the same time, necessitating the addition of make-up water to replace the bleed-off water lost from the system. Also in this type of system such chemical treatments associated with the heat conducting liquid are also disposed down the sewer thereby necessitating additional chemicals along with make-up water to be added to the system. This make-up water normally includes dissolved solids, with less total dissolved solids than the concentrated bleed-off water, thereby reducing the overall total dissolved solids. Calcium and other types of minerals in the water will increase in concentration due to the evaporation of water within the cooling tower necessitating another bleed-off of dissolved solids. If the total dissolved solids is allowed to reach a level of concentration higher than the carrying capacity of the water, the dissolved solids will precipitate and cause scale build-up.
What is needed in the art is a system for cooling tower and heat exchange units in which bleed-off or blow down is eliminated, thereby reducing the need for additional make-up water that would inject new particulate matter, solids, and minerals into the cooling tower heat exchange system.